Hollow point bullets have been used as ammunition for many years. Hollow point bullets combine the advantages of a small-caliber jacket bullet, such as extended trajectory, with that of a large-caliber bullet, such as a high release of kinetic energy into a target. There are a variety of conventional hollow point bullets. Patent application WO 93/07 438 A1 discloses a hollow point bullet having a bore hole with a continuous square cross-section that empties at the tip of the bullet. German patent DE 22 28 733 A1 also shows a hollow point bullet with a bore hole having a continuous square-edged cross-section. The bore hole of the bullet disclosed in DE 22 28 733 A1 is larger than the bore hole of WO 93/07 438 A1 and is filled with lead or plastic. U.S. Pat. No. 5,131,123 discloses a hollow point bullet that is cylindrical. A square-edged cross-section wedge is pressed into the tip and removed to shape the cross-section of the hollow portion. The tip is then pressed again, which creates a coaxial inner bore hole with a square cross-section that almost closes completely at the tip. Similarly, U.S. Pat. No. 5,259,320, which is a divisional of U.S. Pat. No. 5,131,123, more generally discloses an intermediate product that is created in the production of the hollow point bullet.
The hollow point bullet disclosed in German Patent 22 28 733 is a two-part bullet that is particularly useful in the sport of hunting. When this two-part bullet strikes an animal, the front part, which has a hollow tip, separates from the larger back part in the body of the animal. An advantage to this bullet design is that the back part of the bullet typically falls out of the animal, providing an opening through which the blood of the animal can leak. The dripping blood allows the wounded animal to be hunted by a dog more easily. However, a disadvantage with a bullet of this design is that the splinters from the front of the bullet lace large portions of the flesh and bones of the animal.
In the field of law enforcement, police usually use the largest caliber pistols available, such as large-caliber machine pistols, because the objectives of a police officer are different than those of a hunter. A police officer needs to use bullets that have sufficient stopping power without causing unnecessary damage to the body of a suspect or a criminal. Further, with respect to property, structural and surface damage should be low. For example, if a shot hits a wall, the bullet should not penetrate enough to cause damage in areas where the police officer cannot see. A bullet with a caliber that is too small may not transfer sufficient kinetic energy to stop the target. Further, a bullet with a caliber that is too large may cause an unnecessary amount of damage.
From a military point of view, the aforementioned machine pistols are of little value, because they have extremely poor ballistics. For example, it is difficult for a marksman to use a weapon with such ammunition when the striking distance between him and the target changes because as the distance changes, the marksman's hold point needs to be altered accordingly. Modern gun cartridges for military guns and the like have very small calibers (e.g., approximately 4.5 through 5.5 millimeters). These smaller cartridges have several advantages including that marksman does not have to alter his hold point when aiming in close range (e.g., less than approximately 200 meters) because the bullets are fast and light. The marksman also need not concern himself regarding his handling of the weapon when a target approaches or retreats a few meters.
The penetrating power of such modern small cartridges is, from a military point of view, sufficient. For example, these small cartridges would penetrate clear through a flak jacket, which usually protects from pistol bullets, when hit from a distance of 100 meters. However, after these bullets hit the human body, the bullets would continue to fly for several hundred meters. Consequently, very little kinetic energy is transferred to the body to the target. Therefore, a criminal, for example, who had not been killed, may be able to fight even after being shot.